Spiral stairway



(No Model.)

,W. HORROGKS.

SPIRAL STAIRWAY.

No. 348,908. Patented Sept. 7, 1886.

WITNESSES J |NVENTE1FI I fl YM M I PETERs Phoiwhfllagraphen Washmgmm D.c.

UNITED STATES PATENT OFFIcE.

\VILLIAM HORROCKS, OF PHILADELPHIA, PEJNSYLVANIA.

SPIRAL STAI RWAY.

SPLCTLFICATTQN forming part of Letters Patent No. 3&8308, datedSeptember 7, 1886.

Application filed April 20, li-FG. Serial No. 199,531. (No model.)

To all whom it mayconcern.

Be it known that 1', WILLIAM HORROOKS, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inSpiral Stairways; and I do hereby declare the following to be a full,clear, and exact description of the invention, reference being had tothe acconr panying drawings, which form part of this specification, inwhich- Figure 1 is an elevation of a spiral stairway embodying myinvention. Fig. 2 is a vertical detail section of a modification. Fig. 3is a perspective of tread-plate inverted. Fig. 4 is a vertical detailsection. Fig. 5 is a perspective of modified form of tread-plateinverted.

My invention has for its object to provide an improved construction of aspiral stairway made of metal.

My improvements consist in the peculiar construction and combinations ofparts, hereinafter fully described and claimed.

Referring to the accompanying drawings, A represents the central post orcolumn of the stairway, which is composed of metal, and is preferablytubular, although it may be a solid rod.

B 13 represent rounds, which are rods projecting radially from thecentral post, A, and arranged to form a spiral. The rods B B passcompletely through the post A, and are riveted therein. XVhen the postis tubular, the rods are turned, forming shoulders I), which abutagainst the inner walls, a, of the post, and the ends of the rods areriveted on the latter, as shown.

0 represents a metallic strip of spiral form, which connects the outerends of the rounds, said ends passing through openings in the strip, andhaving nuts b" applied thereto, as shown.

D represents the treads, which are of the form shown, having their frontedges bent over, forming hooks or curved flanges d,which embrace therounds. The rear outer end of each of the treads has a projection, (1,forming lugs for the reception of the lower ends of the baluster-rods E.Said baluster-rods pass, as shown, through the outer end of each treadnear its front edge, and also through the lug or projection of the treadbelow.

F represents sleeves or tubes,which encircle the balnster-rods betweenthe tread-plates D, and keep the latter a proper distance apart. Beloweach tread a nut, e, is secured on the lower ends of each of the rods EE.

G represents the hand-rail, which is riveted to the upper ends of thebaluster-rods E E.

The foregoing construction refers to an open stairway without risers;but, if desired, risers may be employed for each of the steps. Saidrisers may be of the form shown in Fi 2, and will consist of metallicplates H H,whose lower edges rest on the treads I) 1) below them, theirupper edges having hooksgg,which hook over the rounds B B. W here saidrisers are employed, they will serve to keep the treads at the properdistance apart, and in such case the tubes surrounding the balustcr-rodsmay' be dispensed with.

If it be desired to make a closed or incased stairway, a sheet of metalof the proper height or width and spirally arranged may be sub stitutedfor the narrow strip G and baluster rods or rails 1D, the outer ends ofthe rounds B B being attached thereto, and a hand-rail,

it desired, being also secured to the inner-side f of the spiral sheet,which latter will form a casing. The casing may be wholly closed byusing a metallic strip of such width that the edges of the spiral willmeet; or it may be of less width, leaving a spiral opening for theentire length of the casing.

The construction described is mainly intended for spiral stairways usedas fire-escapes; but it may be employed in any other case where ametallic spiral stairway is desirable. The post A may rest directly onthe ground or be fastened to any suitable abutment; or it may be causedto rest upon a platform, I, duly fastened to a wall by brackets, braces,or other supports. It will be noticed that the balusters or rods E passthrough the tread-plates just back of the rounds, so that said balusterskeep the treads in position and prevent them from slipping forward offthe rounds.

If desired, I may construct the tread-plate with a lug, (1 for thereception of a bolt, as shown in Fig. 5, by means of which bolt thetread-plate can be secured to the spiral strip 0, thereby dispensingwith the use of sleeves or tubes.

Vhat I claim as my invention is- 1. A spiral stairway consisting of acentral post or column,spirally-arranged radial rounds B B,fastened tosaid post, a spiral strip, 0, securing the outer ends of said rounds andforming a support therefor, and treads supported on said rounds,substantially as shown and described.

2. The treads herein described for stairs, consisting of metallic plateshaving their front edges bent over or turned ovcr,formingcurved flangesor hooks, in combination with rounds B B, substantially as shown anddescribed.

3. The combination, in a spiral stairway, of central post, A,spirally-arranged radial rounds B B, spiral strips 0, treads D, andbalusterrods E, having encircling sleeves or tubes F between each of thetreads, substantially as shown and described.

4, The combination of central post or column, A, spirally-arrangedrounds B, spiral strip O, connecting said rounds, tread-plates D,baluster-rods 1'1, and hand-rail G, substantially as shown anddescribed.

5. The combination, with rounds B and have hereunto set my hand this 9thday of April, 1886.

VILLIAM HORROCKS.

\Vitnesses:

R. DALE SPARI-IAWK, XVILL H. POWELL.

